If you are not big fan of hiking and did not want to spend money on metro and bus tours, this is probably a great option to consider. Admittedly, not all cities have to be visited listing on wheels, but these meet all the requirements.
http://www.huffingtonpost.com/2014/04/12/sightseeing-bike-tours-buenos-aires_n_4952302.html?utm_hp_ref=travel